Inkjet marking ink composition for flexible substrate

Abstract

One embodiment of the present invention relates to a resin composition comprising: (A) a monofunctional (meth)acrylate; (B) a polyfunctional (meth)acrylate; (C) a thermosetting resin; (D) a photopolymerization initiator; and (E) an inorganic filler, wherein the acrylic equivalent weight is 160 g / eq to 280 g / eq. The resin composition according to the present invention can provide an inkjet marking ink composition having excellent flexibility and adhesion when used on a flexible substrate, and capable of suppressing peeling and cracking when folded or bent. In addition, the resin composition can provide an inkjet marking ink composition having excellent storage safety and high adhesion.

Description

Inkjet marking ink composition for flexible substrates

[0001] The present invention relates to an inkjet marking ink composition for a flexible substrate.

[0002] Marking ink is used in the post-process of the solder resist application process of printed circuit board manufacturing before assembling electronic components on a printed circuit board (hereinafter referred to as 'PCB'), and is used to mark characters to be displayed when mounting the circuit board.

[0003] As inkjet utilization increases, not only rigid substrates but also rigid-flexible substrates and flexible substrates are being widely utilized as substrates for applying inkjet compositions. Nevertheless, conventional inventions regarding inkjet compositions have mainly focused on properties related to rigid substrates, such as adhesion, scratch resistance, pencil hardness, and reactivity, and have not focused on properties required for flexible substrates, such as flexibility and bendability.

[0004] When these conventional inkjet compositions are used on flexible substrates, peeling and cracking occur when folded or bent. Furthermore, adhesion to flexible substrates (e.g., polyimide substrates) remains a challenge.

[0005] Meanwhile, for resin compositions, a higher degree of crosslinking improves storage stability (e.g., solvent resistance). However, higher degrees of crosslinking tend to impair adhesion to substrates. Thus, while it's conventional wisdom that both storage stability and adhesion are difficult to achieve, a resin composition that yields a cured product with superior storage stability and high adhesion sufficient for use on flexible substrates is needed.

[0006] [Prior Art Literature]

[0007] (Patent Document 1) Japanese Patent Application Laid-Open No. 2019-522689

[0008] (Patent Document 2) Patent Publication No. 2013-0082159

[0009] The present invention aims to address the above-described problems, and provides an inkjet marking ink composition that exhibits excellent flexibility and adhesion when used on a flexible substrate, and suppresses peeling and cracking when folded or bent. Furthermore, the present invention provides an inkjet marking ink composition that exhibits excellent preservation safety and high adhesion.

[0010] One embodiment of the present invention relates to a resin composition.

[0011] In one aspect, the resin composition comprises (A) a monofunctional (meth)acrylate, (B) a polyfunctional (meth)acrylate, (C) a thermosetting resin, (D) a photopolymerization initiator, and (E) an inorganic filler, and may have an acrylic equivalent of 160 g / eq or more and 280 g / eq or less.

[0012] In one aspect, the (A) monofunctional (meth)acrylate and (B) polyfunctional (meth)acrylate may include a polar functional group capable of forming a cross-linking bond.

[0013] In one aspect, the polar functional group may be at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an amine group, a carbonyl group, an acrylic group, an acryloyl group, a nitrile group, a vinyl group, a halogen group, a urethane group, and an ester group.

[0014] In one aspect, the (A) monofunctional (meth)acrylate may include a (meth)acrylate having a hydroxyl group.

[0015] In one aspect, the (A) monofunctional (meth)acrylate or (B) polyfunctional (meth)acrylate may have an alkylene oxide skeleton.

[0016] In one aspect, the content of (A) monofunctional (meth)acrylate may be 30 to 80 wt% based on the total weight of the resin composition.

[0017] In one aspect, the content of (B) multifunctional (meth)acrylate may be 2 to 45 wt% based on the total weight of the resin composition.

[0018] In one aspect, the (A) monofunctional (meth)acrylate includes a (meth)acrylate having a hydroxyl group, and the content of the (meth)acrylate having a hydroxyl group may be 2 to 50 wt% based on the total weight of the resin composition.

[0019] In one aspect, the (C) thermosetting resin may include a blocked isocyanate.

[0020] In one aspect, the (A) monofunctional (meth)acrylate includes a (meth)acrylate having a hydroxyl group, and the (C) thermosetting resin includes a blocked isocyanate, and the equivalent ratio of the isocyanate and the hydroxyl group may be 1:4 to 1:15.

[0021] In one aspect, the content of the (C) thermosetting resin may be 2 to 15 wt% based on the total weight of the resin composition.

[0022] In one aspect, the photopolymerization initiator (D) may be at least one selected from the group consisting of a phosphine oxide compound, a thioxanthone compound, and a benzoate compound.

[0023] In one aspect, the (E) inorganic filler may be at least one selected from the group consisting of titanium oxide, zinc oxide, carbon black, basic carbonate, basic sulfate, sulfate, zinc sulfide, antimony oxide, aluminum hydroxide, silica, and barium sulfate.

[0024] In another aspect, the resin composition comprises (A) a monofunctional (meth)acrylate, (B) a polyfunctional (meth)acrylate, (C) a thermosetting resin, (D) a photopolymerization initiator, and (E) an inorganic filler, wherein the (A) monofunctional (meth)acrylate comprises a (meth)acrylate having a hydroxyl group, and the (C) thermosetting resin comprises a blocked isocyanate, and the equivalent ratio of the isocyanate and the hydroxyl group may be 1:4 to 1:15.

[0025] In one aspect, the resin composition may be used for forming a marking in a post-process of a photo solder resist (PSR) application process on a printed circuit board.

[0026] Another embodiment of the present invention relates to a printed circuit board having a cured product formed of the resin composition on a substrate.

[0027] A resin composition according to one embodiment of the present invention has an appropriate amount of cross-linking points compared to conventional marking inks by controlling the acrylic equivalent within a specific content range, and the distance between cross-linking points is long, thereby exhibiting the characteristics of high flexibility and high adhesion. Due to these characteristics, the resin composition exhibits excellent flexibility when used as an inkjet marking ink composition on a flexible substrate, and can suppress peeling and cracking when folded or bent.

[0028] Various embodiments of the present invention are described below.

[0029] [Resin composition]

[0030] One embodiment of the present invention relates to a resin composition comprising (A) a monofunctional (meth)acrylate, (B) a polyfunctional (meth)acrylate, (C) a thermosetting resin, (D) a photopolymerization initiator, and (E) an inorganic filler.

[0031] In one aspect, the acrylic equivalent of the resin composition may be 160 g / eq or more and 280 g / eq or less. The acrylic equivalent of the resin composition is the mass of the resin composition per mole of (meth)acrylic groups, and is obtained by dividing the mass (g) of the resin composition by the mole number of (meth)acrylic groups in the resin composition. If the acrylic equivalent of the resin composition is less than 160 g / eq, the resin composition has many cross-linking points between acrylate monomers, the distance between cross-linking points becomes short, resulting in high strength and insufficient flexibility, making it unsuitable for use in a flexible substrate. If the acrylic equivalent of the resin composition exceeds 280 g / eq, there is a problem in that the cross-linking density of photocuring decreases, resulting in lower pencil hardness. The present invention adjusts the acrylic equivalent of the resin composition within a specific range, thereby having an appropriate amount of cross-linking points, sufficiently increasing the distance between cross-linking points, and providing flexibility and appropriate hardness suitable for use in a flexible substrate.

[0032] For example, the resin composition may be used in a post-process of a solder resist application process on a printed circuit board to mark characters displayed when mounting the circuit board.

[0033] Below, each component of the resin composition is described in detail.

[0034] [(meth)acrylate]

[0035] In this specification, “(meth)acrylate” is a general term for acrylates, methacrylates, and mixtures thereof, and the same applies to other similar expressions. Monofunctional (meth)acrylate means a (meth)acrylate having one (meth)acryloyl group, and polyfunctional (meth)acrylate means a (meth)acrylate having two or more (meth)acryloyl groups.

[0036] For example, monofunctional (meth)acrylates include ethyl (meth)acrylate, trifluoroethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, Esters of monohydric alcohols and (meth)acrylic acid, such as tetrahydrofurfuryl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 2-ethylhexyldiethylene glycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, phenol (EO) acrylate, and 3-phenoxybenzyl (meth)acrylate; - 2-Hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, 2-Hydroxybutyl (meth)acrylate, 4-Hydroxybutyl (meth)acrylate, 2-Hydroxy-3-phenoxypropyl (meth)acrylate, Octylacrylate, Nonylacrylate, Isononyl acrylate, 3,3,5-Trimethylcyclohexyl acrylate, Cyclic trimethylolpropane formal acrylate, 1-Naphthalenemethyl (meth)acrylate, 1-Ethylcyclohexyl (meth)acrylate, 1-Methylcyclohexyl (meth)acrylate, 1-Ethylcyclopentyl (meth)acrylate, 1-Methylcyclopentyl (meth)acrylate, Dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate,Tetrahydrodicyclopentadienyl (meth)acrylate, 2-(o-phenylphenoxy)ethyl (meth)acrylate, isobornylcyclohexyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1-adamantyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, 2-methyl-2-adamantanyl (meth)acrylate, 2-ethyl-2-adamantanyl (meth)acrylate, 2-isopropyladamantan-2-yl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, (adamantan-1-yloxy)methyl (meth)acrylate, 2-Isopropyl-2-adamantyl (meth)acrylate, 1-methyl-1-ethyl-1-adamantyl methanol (meth)acrylate, 1,1-diethyl-1-adamantyl methanol (meth)acrylate, 2-cyclohexylpropan-2-yl (meth)acrylate, 1-isopropylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, tetrahydropyranyl (meth)acrylate, tetrahydro-2-furanyl (meth)acrylate, 2-oxotetrahydrofuran-3-yl (meth)acrylate, It may be at least one selected from the group consisting of mono(meth)acrylates of polyhydric alcohols such as (5-oxotetrahydrofuran-2-yl)methyl(meth)acrylate, (2-oxo-1,3-dioxolan-4-yl)methyl(meth)acrylate, 1-ethoxyethyl(meth)acrylate, succinic acid mono(2-acryloyloxyethyl) ester, etc., but is not limited thereto. The monofunctional (meth)acrylate may be one kind of compound or a mixture of two or more different compounds.

[0037] For example, polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, Bifunctional (meth)acrylates such as hydroxypivalic neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, isocyanurate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanuric acid EO-modified di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane Trifunctional (meth)acrylates such as tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, isocyanuric acid EO-modified tri(meth)acrylate, etc., tetrafunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate,It may be at least one selected from the group consisting of (meth)acrylates having five or more functional groups, such as propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate, but is not limited thereto. The multifunctional (meth)acrylate may be one type of compound or a mixture of two or more different compounds.

[0038] In one embodiment of the present invention, the resin composition contains (A) a monofunctional (meth)acrylate and (B) a polyfunctional (meth)acrylate together, thereby having an effect of obtaining viscosity and hardness suitable for inkjet.

[0039] In one aspect, the (A) monofunctional (meth)acrylate and (B) polyfunctional (meth)acrylate may include a polar functional group capable of forming a cross-linking bond. The polar functional group may be at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an amine group, a carbonyl group, an acrylic group, an acryloyl group, a nitrile group, a vinyl group, a halogen group, a urethane group, and an ester group, but is not limited thereto.

[0040] For example, the above (A) monofunctional (meth)acrylate may include a (meth)acrylate having a hydroxyl group. Based on the total weight of the resin composition, the content of the (meth)acrylate having a hydroxyl group may be 2 to 50 wt%, 5 to 50 wt%, 2 to 45 wt%, or 10 to 40 wt%. If it is less than the above range, the hardness may be weakened due to a decrease in adhesion to the substrate or a decrease in crosslinking density, and if it is more than the above range, the occurrence of cracks may increase when folding or bending, and the hardness may be weakened.

[0041] For example, the above (A) monofunctional (meth)acrylate or (B) polyfunctional (meth)acrylate may have a skeleton of alkylene oxide, and flexibility may be improved by including a (meth)acrylate having an alkylene oxide skeleton. For example, the above (A) monofunctional (meth)acrylate or (B) polyfunctional (meth)acrylate may have a skeleton of methylene oxide or ethylene oxide.

[0042] For example, the above (A) monofunctional (meth)acrylate may have improved flexibility by including at least one selected from the group consisting of cyclic trimethylolpropane formal acrylate (CFTA) and isobornyl acrylate (IBXA).

[0043] For example, the above (B) multifunctional (meth)acrylate is pentaerythritol tetraacrylate (Pentaerythritol tetraacrylate, PETRA) and ethylene oxide modified trimethylolpropane triacrylate ((EO) n Trimethylolpropane Triacrylate, (EO) n Hardness and content resistance can be improved by including one or more selected from the group consisting of TMPTA (n is 1 to 6).

[0044] In one embodiment of the present invention, the content of (A) monofunctional (meth)acrylate may be 30 to 80 wt%, 40 to 75 wt%, or 50 to 70 wt%, based on the total weight of the resin composition. The composition may include a solid content and a solvent. When the content of (A) monofunctional (meth)acrylate is 70 wt% or less, based on the total weight of the resin composition, excellent hardness characteristics may be exhibited.

[0045] In one embodiment of the present invention, the content of (B) polyfunctional (meth)acrylate may be 2 to 50 wt%, 5 to 50 wt%, 2 to 45 wt%, 5 to 45 wt%, 6 to 33 wt%, or 8 to 21 wt%, based on the total weight of the resin composition. The composition may include a solid content and a solvent. When the content of (B) polyfunctional (meth)acrylate is 21 wt% or less, based on the total weight of the resin composition, excellent bending resistance may be exhibited. By adjusting the content of (A) monofunctional (meth)acrylate and the content of (B) polyfunctional (meth)acrylate within the above ranges, the acrylic equivalent in the resin composition may be adjusted within a specific range.

[0046] For example, the above (A) monofunctional (meth)acrylate includes a (meth)acrylate having a hydroxyl group, and the content of the (meth)acrylate having a hydroxyl group may be 5 to 50 wt% or 6 to 45 wt% based on the total weight of the resin composition.

[0047] [(C) thermosetting resin]

[0048] Any known thermosetting resin can be used. In the present invention, the resin composition can improve the heat resistance of the cured coating film by including a thermosetting resin. Examples of the thermosetting resin include known and commonly used ones such as epoxy resins, isocyanate compounds, blocked isocyanate compounds, amino resins, polyfunctional oxetane compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, and episulfide resins. The thermosetting resins can be used singly or in combination of two or more.

[0049] For example, (C) the thermosetting resin may be a blocked isocyanate. As the blocked isocyanate, an addition reaction product of an isocyanate and an isocyanate blocking agent is used. The blocked isocyanate may be at least one selected from difunctional or trifunctional groups. Difunctional or trifunctional means having two or three isocyanate groups protected by a blocking agent.

[0050] Examples of isocyanate structures that can react with isocyanate blocking agents include isocyanurate type, biuret type, and adduct type.

[0051] Specific examples of isocyanates include aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylene isocyanate, m-xylene isocyanate, and 2,4-tolylene dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylene bis(cyclohexyl isocyanate), and isophorone diisocyanate; and alicyclic polyisocyanates such as bicycloheptane triisocyanate.

[0052] Examples of the isocyanate blocking agent used in the blocked isocyanate include phenol blocking agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-parelolactam, γ-butyrolactam, and β-propiolactam; active methylene blocking agents such as ethyl acetoacetate and acetylacetone; alcohol blocking agents such as methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl ether, methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate, and ethyl lactate; Oxime blocking agents such as formaldehyde doxime, acetaldoxime, acetoxime, methylethylketoxime, diacetylmonoxime, and cyclohexane oxime; mercaptan blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, and ethylthiophenol; acid amide blocking agents such as acetic acid amide and benzamide; imide blocking agents such as succinimide and maleimide; amine blocking agents such as xylidine, aniline, butylamine, and dibutylamine; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine; pyrazole blocking agents such as dimethyl pyrazole; maleic acid ester blocking agents such as diethyl maleic acid; Examples of active ester blocking agents include phenol esters, thiophenol esters, N-hydroxylamine esters, and esters of heterocyclic hydroxy compounds.

[0053] As block isocyanates, commercially available ones include, for example, Desmodule (registered trademark) BL-3175, BL-4265, BL-1100 / 1, BL-1265 / 1, TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117, Desmosam 2170, Desmosam 2265 (all manufactured by Sumitomo Bayer Urethane Co., Ltd.), Coronate (registered trademark) 2512, Coronate 2513, Coronate 2520 (all manufactured by Tosoh Corporation), B-830, B-815, B-846, B-870, B-874, B-882 (all manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), Duranate. Examples thereof include SBN-70D, TPA-B80E, 17B-60P, E402-B80B, MF-K60B, SBB-70P, SBB-70D, MF-B60B (all manufactured by Asahi Kasei Co., Ltd.), TRIXENE BI 7982, 7950, 7951, 7960, and 7961 (manufactured by Baxenden Chemicals Limited). In addition, DESMODULE BL-3175 and BL-4265 are obtained using methylethyl oxime as a blocking agent. One of these can be used alone, or two or more can be used in combination.

[0054] For example, in the resin composition of the present invention, (A) the monofunctional (meth)acrylate includes a (meth)acrylate having a hydroxyl group, and (C) the thermosetting resin includes a blocked isocyanate, and the equivalent ratio of the isocyanate to the hydroxyl group may be 1:4 to 1:15. The hydroxyl equivalent of the resin composition is the mass of the resin composition per mole of hydroxyl group, and is obtained by dividing the mass (g) of the resin composition by the number of moles of hydroxyl group in the resin composition. The isocyanate equivalent of the resin composition is the mass of the resin composition per mole of isocyanate, and is obtained by dividing the mass (g) of the resin composition by the number of moles of isocyanate in the resin composition. When the hydroxyl equivalent ratio is in the range of 4 to 15 hydroxyl equivalents per 1 isocyanate equivalent, adhesion, flexibility, and sufficient film strength can be obtained. If the hydroxyl equivalent is less than 4, the number of hydroxyl groups decreases, resulting in reduced adhesion and poor storage stability. On the other hand, if the hydroxyl equivalent exceeds 15, the crosslinking density decreases, making it difficult to develop film strength.

[0055] In the resin composition of the present invention, the content of the thermosetting resin (C) may be 2 to 15 wt%, 3 to 13 wt%, or 4 to 12 wt%, based on the total weight of the resin composition. The composition may include a solid content and a solvent.

[0056] (C) When the content of the thermosetting resin is within the above range, there is an effect of obtaining appropriate adhesion and hardness.

[0057] In the resin composition of the present invention, the content of the blocked isocyanate may be 2 to 15 wt%, 3 to 13 wt%, or 4 to 12 wt%, based on the total weight of the resin composition. The composition may include a solid content and a solvent.

[0058] [(D) Photopolymerization initiator]

[0059] There are no particular limitations on the photopolymerization initiator, as long as it can polymerize (meth)acrylate upon irradiation with energy rays. A radical polymerization initiator can be used. For example, there are no particular limitations on the photopolymerization initiator, as long as it absorbs light in the wavelength range of 350 nm to 450 nm. One type of photopolymerization initiator may be used alone, or two or more types may be used in combination.

[0060] Specific examples of the photopolymerization initiator include bisacylphosphine oxides such as bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; Monoacylphosphine oxides such as 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate; Hydroxyacetophenones such as 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; Benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone;Acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, and N,N-dimethylaminoacetophenone; Thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethylbenzoate, and p-dimethylbenzoic acid ethyl ester; Oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); titanocenes such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrrol-1-yl)ethyl)phenyl]titanium, and bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene; Examples include phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, and tetramethylthiuram disulfide.

[0061] Commercially available products of α-aminoacetophenone-based photopolymerization initiators include Omnirad 907, 369, 369E, 379, and Esacure ONE manufactured by IGM Resins. In addition, commercially available products of acylphosphine oxide-based photopolymerization initiators include Omnirad TPO, TPO-L, and 819 manufactured by IGM Resins, and Mosaphoto 348 manufactured by UFC Corporation. Commercially available products of oxime ester photopolymerization initiators include Irgacure OXE01 and OXE02 manufactured by BASF Japan Co., Ltd., N-1919 and ADEKA Acruze NCI-831 and NCI-831E manufactured by ADEKA Co., Ltd., and TR-PBG-304 manufactured by Changzou Tronly New Electronic Materials Co., Ltd. Commercial products of thioxanthone photopolymerization initiators include ITX manufactured by Zhejiang Shou & Fu Chemtrade Co., Ltd. Commercial products of titanocene photopolymerization initiators include Mosaphoto 533 manufactured by UFC Corporation.

[0062] For example, the photopolymerization initiator (D) may be at least one selected from the group consisting of a phosphine oxide-based compound, a thioxanthone-based compound, and a benzoate-based compound. For example, if the photopolymerization initiator (D) is an acylphosphine oxide-based compound or a thioxanthone-based compound, curing of the resin composition is possible with LED light of 365 to 395 nm.

[0063] In the resin composition of the present invention, the content of the (D) photopolymerization initiator may be 0.1 to 10 wt%, 0.1 to 5 wt%, or 1 to 5 wt% based on the total composition. The composition may include a solid content and a solvent.

[0064] When the content of the photopolymerization initiator is 0.1 wt% or more, the photocurability of the resin composition improves, and the coating properties, such as chemical resistance, also improve. On the other hand, when the content is 10 wt% or less, light absorption at the surface of the resist film (cured coating film) improves, making it difficult for deep curing properties to deteriorate.

[0065] In combination with the above-mentioned photopolymerization initiator, a photoinitiation aid or sensitizer may be used. Examples of the photoinitiation aid or sensitizer include benzoin compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds. In particular, thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone can be used. By including a thioxanthone compound, deep curing property can be improved. These compounds can be used as photopolymerization initiators, but can also be used in combination with a photopolymerization initiator. In addition, the photoinitiation aid or sensitizer may be used alone or in combination of two or more types.

[0066] Furthermore, since these photopolymerization initiators, photoinitiation aids, and sensitizers absorb specific wavelengths, in some cases, sensitivity is lowered and they function as ultraviolet absorbers. However, they are not used solely for the purpose of improving the sensitivity of the resin composition. If necessary, they can increase the photoreactivity of the surface by absorbing light of a specific wavelength, change the line shape and aperture of the resist pattern to a vertical, tapered, or reverse taper shape, and also improve the precision of the line width or aperture diameter.

[0067] [(E) Weapon Refill]

[0068] A resin composition according to one embodiment of the present invention is used to improve properties such as adhesion and hardness by including an inorganic filler. In addition, the inorganic filler can be used as a colorant.

[0069] The inorganic filler may include, for example, one or more selected from the group consisting of titanium oxide, zinc oxide, carbon black, basic carbonates, basic sulfates, sulfates, zinc sulfide, antimony oxide, aluminum hydroxide, silica, and barium sulfate.

[0070] For example, the manufacturing method of titanium oxide can be either the sulfuric acid method or the chlorine method, and for example, the chlorine method may be used. For example, the manufacturing process may not use sulfuric acid. Furthermore, the surface treatment of titanium oxide is not particularly limited, but may be titanium oxide treated with an acid other than sulfuric acid, such as hydrochloric acid, nitric acid, phosphoric acid, or acetic acid, during neutralization.

[0071] The titanium oxide may be of any structure, including rutile, anatase, and Ramsdelight types, and may be used alone or in combination of two or more types. Among these, Ramsdelight type titanium oxide is Ramsdelight type Li. 0.5 TiO2 can be obtained by performing chemical lithium oxide removal treatment.

[0072] Among the above, the use of rutile-type titanium oxide can further improve heat resistance, make it difficult for discoloration due to light irradiation to occur, and make it difficult for quality to deteriorate even in a strict usage environment. In particular, the heat resistance can be improved by using rutile-type titanium oxide surface-treated with aluminum oxide such as alumina. The content of rutile-type titanium oxide surface-treated with aluminum oxide in the total titanium oxide is, for example, 35 mass% or more, for example, 55 mass% or more, and the upper limit is 100 mass% or less, that is, the entire amount of titanium oxide may be rutile-type titanium oxide surface-treated with the above aluminum oxide. In addition, since anatase-type titanium oxide has a lower hardness than rutile-type titanium oxide, the formability of the composition is further improved when anatase-type titanium oxide is used.

[0073] (E) Among the inorganic fillers, the sulfur concentration of titanium oxide may be 100 ppm or less, or 50 ppm or less. In addition, commercially available titanium oxide having a sulfur concentration of 100 ppm or less may be used, or commercially available titanium oxide having a sulfur concentration of 100 ppm or more may be mixed and mixed by lowering the sulfur concentration through heat treatment, chemical treatment, washing, calcination, or other purification treatments. Here, the sulfur contained in the titanium oxide refers to all sulfur detected through analysis. It includes sulfur adsorbed on the titanium oxide and sulfur coated on the titanium oxide as an impurity. In addition, the sodium concentration of the titanium oxide may be 100 ppm or less, or 50 ppm or less. The lower the sodium concentration, the better. If the sodium concentration is too high, corrosion or oxidation may be promoted when the copper substrate is exposed to moisture due to sodium ions. For this reason, the concentration of sodium ions may be less than 100 ppm.

[0074] In addition, the photosensitive resin composition of the present invention may contain titanium oxide having a sulfur concentration of 100 ppm or more, as long as the effects of the present invention are not impaired. Titanium oxide having a sulfur concentration of 100 ppm or more includes CR-58, CR-90, and R-630 from Isahara Sangyo Co., Ltd., and R-21 from Sakai-chem Co., Ltd.

[0075] In addition, rutile type chlorinated titanium dioxide T-550, T-580, R-630, R-820, CR-50, CR-60, R-90, CR-97 manufactured by Ishihara Sangyo Co., Ltd., Ti PURE R-706, R-902+, R931 manufactured by DuPont, Tiona 568, Tiona 595 manufactured by Millenium Chemicals, TR-600, TR-700, TR-840 manufactured by Fuji Titanium Industry Co., Ltd., KR-270, KR-310, KR-380 manufactured by Titanium Industry Co., Ltd., etc. can be used.

[0076] If the particle size of titanium oxide is too small, fluidity may be poor, and conversely, if it is too large, insertion into small diameter substrates may be poor. Considering these factors, the median particle size of the titanium oxide is in the range of 0.1 to 5 μm, for example, in the range of 0.1 to 1 μm, for example, in the range of 0.1 to 0.5 μm, and may be 0.20 μm to 0.36 μm. When the particle size of the titanium oxide is within the above range, stable discharge performance can be achieved. The above particle size was measured using a laser diffraction method.

[0077] (E) Among inorganic fillers, barium sulfate includes precipitated barium sulfate #100, precipitated barium sulfate #300, precipitated barium sulfate SS-50, BARIACE B-30, BARIACE B-31, BARIACE B-32, BARIACE B-33, BARIACE B-34, BARIFINE BF-1, BARIFINE BF-10, BARIFINE BF-20, BARIFINE BF-40 (manufactured by Sakai Kagaku Kogyo Co., Ltd.), W-1, W-6, W-10, C300 (manufactured by Takehara Kagaku Kogyo Co., Ltd.).

[0078] (E) Among inorganic fillers, silica particles are not particularly limited and can be obtained by a method known to those skilled in the art. For example, they can be manufactured by burning silicon powder using the VMC (Vaporized Metal Combustion) method. The VMC method is a method in which a chemical flame is formed by a burner in an atmosphere containing oxygen, and a metal powder constituting a portion of the target oxide particle is injected into the chemical flame in an amount that forms a dust cloud, thereby causing knocking to obtain oxide particles. Examples of commercially available silica include the SO series manufactured by Admatex Co., Ltd. and the HPS series manufactured by Toagosei Co., Ltd. (HPS-0500, HPS-1000, HPS3500, etc.).

[0079] (E) Among the inorganic fillers, carbon black can be used as a black-based colorant. Specifically, the carbon black may have a particle diameter of more than about 0 nm and less than or equal to about 30 nm, for example, from about 10 nm to about 30 nm. The particle diameter of the carbon black can be derived by measuring the diameter of the projected image when the carbon black is projected with parallel light in a certain direction. When the particle diameter of the carbon black satisfies the above range, the dispersibility within the resin composition is improved. Examples of the carbon black include Carbon Black, M-40, M-45, M-50, MA-8, and MA-100 manufactured by Mitsubishi Chemical Corporation, and Carbon Black 1255 manufactured by Columbia Chemical Company.

[0080] For example, (E) there is no particular limitation on the inorganic filler, but when titanium oxide is used, it can be used in combination with a photopolymerization initiator that absorbs light at 350 nm to 450 nm, and from the viewpoint of coloring, it can be used in combination with a photopolymerization initiator of an acylphosphine oxide compound.

[0081] In the photosensitive resin composition of the present invention, the blending amount of the (E) inorganic filler may be in the range of 1 to 30 mass%, for example, in the range of 1.5 to 25 mass%, for example, in the range of 1.5 to 20 mass%, relative to the entire resin composition. When the content of the (E) inorganic filler is within the above range, an improvement in physical strength can be expected, and a decrease in (inkjet) printability due to an increase in viscosity or an increase in thixotropic properties can be suppressed.

[0082] [Other optional ingredients]

[0083] The resin composition of the present invention may contain, as necessary, one or more of the following materials as optional components.

[0084] Epoxy resin

[0085] The epoxy resin of the present invention may be a known, commonly used compound having one or more epoxy groups. For example, it may be a compound having two or more epoxy groups. For example, it may be a compound having two or more epoxy groups in one molecule, such as a monoepoxy compound such as butyl glycidyl ether, phenyl glycidyl ether, and glycidyl (meth)acrylate, bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, aliphatic ring epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl ether of ethylene glycol or propylene glycol, sorbitol polyglycidyl ether, tris(2,3-epoxypropyl)isocyanurate, triglycidyltris(2-hydroxyethyl)isocyanurate. These can be used alone or in combination of two or more types to suit the required characteristics.

[0086] Antioxidant

[0087] The resin composition of the present invention may also contain an antioxidant. By including an antioxidant, not only can the curable resin and other materials be prevented from oxidative deterioration and discoloration be suppressed, but heat resistance can also be improved and resolution (line width reproducibility) can be improved. Specifically, depending on the type of white colorant, there are cases where resolution is impaired by reflecting and absorbing light. However, by including an antioxidant, good resolution can be achieved regardless of the type of white colorant.

[0088] Colorant

[0089] The resin composition of the present invention may contain a colorant.

[0090] Examples of black-based colorants include, in addition to carbon black, inorganic pigments such as iron tetroxide (Fe3O4), titanium black oxide, copper manganese black, copper chromium black, and cobalt black, as well as organic pigments such as cyanine black and aniline black. Furthermore, other colorants include commonly known red, blue, green, and yellow pigments or dyes.

[0091] The content of the colorant in the resin composition of the present invention is approximately 1.0 to 25.0 mass%, for example, 2.0 to 15.0 mass%, with respect to the entire resin composition.

[0092] Other additives

[0093] In addition, the resin composition of the present invention may contain other commonly known additives in the field of electronic materials. Examples of such additives include thermal polymerization inhibitors, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, anti-aging agents, antibacterial and antifungal agents, antifoaming agents, leveling agents, thickeners, fluidity additives, adhesion-imparting agents, thixotropic agents, photoinitiation aids, sensitizers, curing accelerators, release agents, surface treatment agents, dispersants, dispersing aids, surface modifiers, stabilizers, diluents, and the like.

[0094] [Curing agent and its manufacturing method]

[0095] The cured product of the present invention can be formed by curing the resin composition of the present invention.

[0096] The cured product of the present invention can be suitably used for printed circuit boards, electronic components, and the like. The cured product of the present invention can be used for forming markings in a post-process of applying solder resist on a printed circuit board. When used on a flexible substrate, the cured product of the present invention exhibits excellent flexibility and suppresses peeling and cracking when folded or bent.

[0097] In addition, a cured film having excellent properties such as adhesion and hardness can be formed by i) irradiating the cured product with an active energy ray and then heat-curing (e.g., 100 to 220°C) or ii) irradiating the cured product with an active energy ray after heat-curing.

[0098] <Example>

[0099] Hereinafter, the present invention will be described in detail using examples. The present invention is not limited to the following examples.

[0100] Preparation of inkjet marking ink composition

[0101] The raw materials were placed in a container and stirred to prepare a composition. The contents of each component are as shown in Table 1 below.

[0102] Table 1. Content of each component of the composition (unit: parts by weight relative to the entire composition)

[0103]

[0104] The details of each component shown in Table 1 above are as follows.

[0105]

[0106] Manufacturing of flexible marking ink substrates

[0107] First, a Kapton (registered trademark) polyimide flexible substrate manufactured by Toray DuPont, Inc., measuring 100 mm in length × 150 mm in width was prepared. Next, the inkjet marking ink compositions manufactured in the examples and comparative examples were applied to an inkjet printer (Microcraft MJP2013K1-DU) with a piezoelectric type print head, and coated on the polyimide flexible substrate. Thereafter, the inkjet marking ink composition coated on the polyimide flexible substrate was irradiated with a total accumulated light dose of 400 mJ / cm using a UV LED lamp (385 nm, 395 nm) attached to the inkjet printer. 2Photocuring was performed while irradiating with ultraviolet rays. After the photocuring, thermal curing was performed at a temperature of 150°C for 60 minutes in a hot air circulation drying oven to produce a marking ink film.

[0108] The marking ink film manufactured as described above was evaluated as follows, and the inkjet marking ink compositions of the examples and comparative examples were evaluated. The evaluation results are shown in Table 2.

[0109] 1. Hajeori test

[0110] The 180° bending was repeated twice by Hajeori, and the occurrence of cracks was observed with the naked eye and under an optical microscope (magnification Х200), and the number of times cracks occurred was evaluated.

[0111] ◎: 0 cracks

[0112] ○: 1 small crack

[0113] △: 1 crack

[0114] ×: 2 or more cracks

[0115] 2. MIT exam

[0116] Using an MIT Endurance Fatigue Tester Type D (manufactured by Toyo Seiki Seisakusho Co., Ltd.), an MIT test was conducted in accordance with JIS P8115 to evaluate flexural properties. Under a load (0.5 kgf), the specimen was vertically attached to the clamp, and bending was performed at a bending angle of 135° and a speed of 175 RPM. The number of reciprocating bending cycles until fracture was measured. Flexural properties were evaluated using the following criteria.

[0117] ◎: More than 100 times

[0118] ○: 50 times or more but less than 100 times

[0119] △: 10 times or more but less than 50 times

[0120] ×: Less than 10 times

[0121] 3. Adhesion of marking ink

[0122] Using a knife, make 100 square (□)-shaped marks (10X10) at a 30° angle on the surface of the marking ink film, 1 mm wide, adhere with adhesive tape, and then immediately remove. After removing, the adhesiveness was evaluated according to the shape of the marks that fell off according to the figure below.

[0123]

[0124] ◎:5B

[0125] ○: 4B

[0126] △:3B

[0127] ×: 2B or less

[0128] 4. Pencil hardness

[0129] A pencil of grade B to 9H sharpened to make the end of the core flat was pressed at an angle of approximately 45°, and the hardness of the pencil without peeling of the coating was recorded and evaluated according to the following criteria.

[0130] 6H and above: ◎

[0131] 5H or higher: ○

[0132] 4H or higher: △

[0133] 3H or higher: ×

[0134] 5. Preservation stability

[0135] The initial viscosity of the inkjet ink composition was measured, stored in a sealed container at 50°C for two weeks, and then the viscosity was measured again to check the viscosity change according to the following formula to evaluate the storage stability.

[0136] ceremony : (A = initial viscosity, B = viscosity after 2 weeks of storage)

[0137] The viscosity change calculated by the above formula was evaluated based on the criteria below.

[0138] Viscosity change: 0% or more but 8% or less: ○

[0139] Viscosity change of 8% to 15%: △

[0140] Viscosity change exceeding 15%: X

[0141] Table 2. Evaluation Results

[0142]

[0143] Since the acrylic equivalent of the resin compositions of Examples 1 to 5 is 160 g / eq or more and 280 g / eq or less, it can be seen that peeling and cracking are suppressed when folding or bending a coating film using the compositions, and flexibility, adhesion, and hardness are excellent.

[0144] Meanwhile, when the resin compositions of Comparative Examples 1 to 3 and 5 to 7 having an acrylic equivalent of less than 160 g / eq and the resin composition of Comparative Example 4 having an acrylic equivalent of more than 280 g / eq are used, it can be confirmed that many cracks occur, the bending resistance is poor, and the adhesion of the coating film to the substrate is also poor.

[0145] In addition, it can be confirmed that Comparative Examples 1 to 3 do not contain blocked isocyanate, and thus have low strength and cracks. It can be confirmed that Comparative Examples 2 to 4 do not contain (meth)acrylate having a hydroxyl group, and thus have low flexibility and adhesion. It can be confirmed through Comparative Example 4 that when the equivalence ratio (OH / NCO) exceeds 15, the crosslinking density decreases, making it difficult to develop the strength of the coating film, and it can be confirmed through Comparative Examples 5 and 6 that when the equivalence ratio (OH / NCO) is less than 4, the adhesion decreases and also the storage stability worsens.

Claims

1. (A) Monofunctional (meth)acrylate, (B) multifunctional (meth)acrylate, (C) thermosetting resin, (D) Photopolymerization initiator and (E) Contains a weapon charge, A resin composition having an acrylic equivalent of 160 g / eq or more and 280 g / eq or less.

2. A resin composition according to claim 1, wherein the (A) monofunctional (meth)acrylate and (B) polyfunctional (meth)acrylate contain a polar functional group capable of forming a cross-linking bond.

3. In the second paragraph, the polar functional group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an amine group, a carbonyl group, an acrylic group, an acryloyl group, a nitrile group, a vinyl group, a halogen group, a urethane group, and an ester group.

4. In the first paragraph, the (A) monofunctional (meth)acrylate is a resin composition comprising a (meth)acrylate having a hydroxyl group.

5. A resin composition according to claim 1, wherein the (A) monofunctional (meth)acrylate or (B) polyfunctional (meth)acrylate has an alkylene oxide skeleton.

6. A resin composition in which the content of (A) monofunctional (meth)acrylate is 30 to 80 wt% based on the total weight of the resin composition in the first paragraph.

7. A resin composition in which the content of (B) multifunctional (meth)acrylate is 2 to 45 wt% based on the total weight of the resin composition in the first paragraph.

8. In the first paragraph, the (A) monofunctional (meth)acrylate includes a (meth)acrylate having a hydroxyl group, and the content of the (meth)acrylate having a hydroxyl group is 5 to 50 wt% based on the total weight of the resin composition.

9. A resin composition according to claim 1, wherein the thermosetting resin (C) comprises a blocked isocyanate.

10. A resin composition in the first paragraph, wherein the (A) monofunctional (meth)acrylate comprises a (meth)acrylate having a hydroxyl group, and the (C) thermosetting resin comprises a blocked isocyanate, and the equivalent ratio of the isocyanate and the hydroxyl group is 1:4 to 1:

15.

11. A resin composition in which the content of the thermosetting resin (C) is 2 to 15 wt% based on the total weight of the resin composition in the first paragraph.

12. A resin composition in the first paragraph, wherein the photopolymerization initiator (D) is at least one selected from the group consisting of a phosphine oxide compound, a thioxanthone compound, and a benzoate compound.

13. A resin composition according to claim 1, wherein the (E) inorganic filler is at least one selected from the group consisting of titanium oxide, zinc oxide, carbon black, basic carbonate, basic sulfate, sulfate, zinc sulfide, antimony oxide, aluminum hydroxide, silica, and barium sulfate. 14.(A) Monofunctional (meth)acrylate, (B) multifunctional (meth)acrylate, (C) thermosetting resin, (D) Photopolymerization initiator and (E) Contains a weapon charge, A resin composition wherein the above (A) monofunctional (meth)acrylate comprises a (meth)acrylate having a hydroxyl group, and the above (C) thermosetting resin comprises a blocked isocyanate, and the equivalent ratio of the isocyanate and the hydroxyl group is 1:4 to 1:

15.

15. A resin composition according to any one of claims 1 to 14, wherein the resin composition is for forming a marking in a post-process of a photo solder resist (PSR) application process on a printed circuit board.

16. A printed circuit board having a cured product formed from a resin composition according to any one of claims 1 to 14 on a substrate.

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